This invention relates to a holder of a test piece that is mounted on a fatigue tester for performing a fatigue test on the constituent material of said test piece by applying cycles of tensile and compressive loads to the piece as it is placed in a hot vacuum, or an inert gas atmosphere.
To collect data on the endurance characteristics of metallic and other materials, the fatigue life of those materials is measured with cyclic loads being applied to the test piece as it is mounted on a fatigue tester.
The measurement of fatigue life has conventionally involved the use of a sample holder having the construction shown in FIG. 1; the thicker portion of a test piece indicated by 1 is retained by a fixing adapter 2, which is fitted in a groove cut in a fixing plate 3 in such a way that the distal end of the test piece is inserted through a center hole in the plate 3. The test piece fixing plate 3 carrying the test piece 1 and the adapter 2 is secured to the fatigue tester by manually tightening screws 4.
When performing the fatigue test, the test piece mounted on the fatigue tester is provided with cycles of tensile and compressive loads and hence it has been necessary to securely fix the test piece in position by means of a sample holder.
Particularly in the case where it is exposed to neutron radiations in nuclear reactors and other radioactive environments, the test piece becomes radioactive and to protect the worker from the emitted radiations, tile operations of mounting and dismounting the test piece have had to be done remotely (by use of manipulators).
Fatigue tests recently require prolonged exposure times; in addition, they are conducted at elevated temperatures and this increases the likelihood that corrosion will occur in the test piece. To avoid these problems, it has recently become desirable to conduct a fatigue test either in vacuo or in an inert gas atmosphere.
In this case, too, the fatigue test must be conducted with a plurality of test pieces being replaced as required without destroying the vacuum or inert atmosphere; a need has, therefore, arisen to perform remote manipulation in connection with the mounting or dismounting of the test piece.